Splittings of infinite abelian group. (Short Communication).
Starre, kippende, wackelige und bewegliche Gelenkvierecke im Raum.
Steinhaus chessboard theorem
Stokes matrices of hypergeometric integrals
In this work we compute the Stokes matrices of the ordinary differential equation satisfied by the hypergeometric integrals associated to an arrangement of hyperplanes in generic position. This generalizes the computation done by J.-P. Ramis for confluent hypergeometric functions, which correspond to the arrangement of two points on the line. The proof is based on an explicit description of a base of canonical solutions as integrals on the cones of the arrangement, and combinatorial relations between...
Strictly convex drawings of planar graphs.
Subsets of the unit ball the are separated by more than one
Substitutions, abstract number systems and the space filling property
In this paper we study multi-dimensional words generated by fixed points of substitutions by projecting the integer points on the corresponding broken halfline. We show for a large class of substitutions that the resulting word is the restriction of a linear function modulo and that it can be decided whether the resulting word is space filling or not. The proof uses lattices and the abstract number system associated with the substitution.
Successive Minima, Intrinsic Volumes, and Lattice Determinants.
Successive-Minima-Type Inequalities.
Sums of distances between points of a sphere.
Sumsets of finite Beatty sequences.
Supersolvable orders and inductively free arrangements
In this paper, we define the supersolvable order of hyperplanes in a supersolvable arrangement, and obtain a class of inductively free arrangements according to this order. Our main results improve the conclusion that every supersolvable arrangement is inductively free. In addition, we assert that the inductively free arrangement with the required induction table is supersolvable.
Support properties of a family of connected compact sets
A problem of finding a system of proportionally located parallel supporting hyperplanes of a family of connected compact sets is analyzed. A special attention is paid to finding a common supporting halfspace. An existence theorem is proved and a method of solution is proposed.
Surface Projective Convexe de volume fini
Une surface projective convexe est le quotient d’un ouvert proprement convexe de l’espace projectif réel par un sous-groupe discret de . Nous donnons plusieurs caractérisations du fait qu’une surface projective convexe est de volume fini pour la mesure de Busemann. On en déduit que si n’est pas un triangle alors est strictement convexe, à bord et qu’une surface projective convexe est de volume fini si et seulement si la surface duale est de volume fini.
Symmetric Laman theorems for the groups and .
Symmetric simplicial pseudoline arrangements.
Symmetries of woven fabrics
Symmetry breakings of the cube tiling and the spatial chess board by - symbols.
Symmetry groups and fundamental tilings for the compact surface of genus . II: The normalizer diagram with classification.
Symplectic packings in cotangent bundles of tori.